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(11) | EP 0 130 075 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Space heating apparatus and valve assemblies therefor |
| (57) A double line central heating system is provided with separate flow and return valve
assemblies (16, 18) for each radiator. Each valve assembly comprises a bypass (91,51)
in a horizontally elongated housing portion for connection to the flow and return
lines (12, 14) respectively. Modem flexible tubing of soft thin-walled copper or steel
or of plastics may be used for the flow and return lines and all joints are readily
accessible; joints underfloor or otherwise inaccessible are avoided. |
[0002] For a number of years modern continuous flexible soft thin-walled copper or steel tubing or plastics tubing has been used to advantage for the pipework of central heating systems of the single line type: such pipework is convenient to install and leaks are minimized. However this pipework has not generally been adopted for systems of the double line type. In a conventional double-line system multiple connections are required since each heating unit must be connected separately to the flow and return lines which are often underfloor, whereas in a single line system with modern continuous pipework there are no underfloor joints required. The compression fittings usual in single line systems are totally unacceptable for underfloor applications on account of the risk of leakage.
[0003] It is one object of the present invention to provide an improved space heating apparatus suitable for use in a double line central heating system and in which advantage can be taken of modern pipework.
[0004] The invention provides space heating apparatus adapted to be connected in a central heating system of the double line fluid flow type, the apparatus comprising a space heating unit (e.g. a radiator of the hot water type), a flow valve assembly adapted to connect the heating unit to a flow line of the central heating system, and a return valve assembly adapted to connect the heating unit to a return line of the central heating system; each valve assembly comprising a bypass passage series-connectible to the flow or return line respectively, and a branch passage connecting the bypass passage to the heating unit, characterised in that the return valve assembly is separate from the flow valve assembly, and each valve assembly comprises a housing portion which is elongated along an axis (e.g. the axis of a lower horizontal radiator duct) about which the valve assembly is mechanically secured to the heating unit and in which elongated portion is provided the bypass passage.
[0005] The axis about which the flow valve assembly is secured to the heating unit is usually, but not necessarily, coaxial with the axis about which the return valve is secured.
[0006] The invention also comprehends a flow or return valve assembly adapted for use in apparatus according to the invention, the valve assembly comprising a bypass passage, series connectible to the flow or return line and a branch passage adapted to connect the bypass passage to the heating unit, characterised in that the valve assembly comprises a housing portion which is elongated along an axis (e.g. the axis of a lower horizontal radiator duct) about which the valve assembly is mechanically securable to the heating unit, the bypass passage is provided in the elongated portion and extends along said axis; and the branch passage comprises an end portion which is directly mechanically securable to the heating unit, is provided in said elongated housing portion coaxially with the bypass passage, and is isolated from the bypass passage by a fixed transverse barrier.
[0007] The invention also comprehends a double line central heating system comprising a plurality of heating units, flow valve assemblies, and return valve assemblies according to the invention. The flow and return lines to which the valve assemblies are connected are e.g. of flexible tubing (e.g. of soft thin-walled copper, or steel or of plastics) with all joints (which are e.g. compression joints) readily accessible.
[0008] There now follows a description, to be read with reference to the accompanying drawings of double line central heating systems embodying the invention. This description is given by way of example only, and not by way of limitation of the invention.
[0009] In the accompanying drawings:
Figure 1 shows partly diagrammatically a flow arrangement to a central heating radiator;
Figure 1A shows a section on the line 1A-1A of Figure 1;
Figure 1B shows a section on the line 1B-1B of Figure 1;
Figure 2 shows a flow diagram of a double line central heating system;
Figure 3 shows an overall view of the flow arrangement of Figure 1;
Figure 4 shows a compression-type pipe fitting;
Figure 5 shows a flow arrangement similar to Figure 1 incorporating modified valve assemblies;
Figure 6 shows a modified flow arrangement;
Figure 7 shows an enlarged view of parts of Figure 6; and
Figures 8, 9 and 10 show partial flow diagrams of modified central heating systems.
[0010] The apparatus embodying the invention comprises a plurality of space heating radiators 10 (an upstream one of which is shown in Figure 1), and flow and return lines 12, 14 respectively leading to and from a hot water boiler 15 (Figure 2).
[0011] The apparatus also comprises a flow valve assembly 16 mechanically secured in conventional fashion to the right hand side of each radiator 10 and a return valve assembly 18 separate from the flow valve assembly 16; the return valve assembly 18 being mechanically secured to the left hand side of the radiator 10; each valve assembly 16, 18 is secured to the radiator 10 about the axis of the lower horizontal duct 11 of the radiator 10. The valve assemblies 16, 18, connect the radiator to the flow and return lines 12, 14 respectively and the flow paths are indicated in the drawings.
[0012] The return valve assembly 18 comprises a thermostatically operated main control valve 20, and a throttle valve 22 for flow balancing purposes. The flow valve assembly 16 comprises an isolation valve 24 for radiator isolating purposes.
[0013] The control valve 20 and the throttle valve 22 are mounted in a housing 23 of integral construction the horizontally extending portion of which is elongated along the axis of the duct 11. The housing 23 comprises a horizontal bore 25 which is co-axial with the duct 11, and a separate horizontal bore 27 which extends in the housing 23 parallel to the bore 25; a third bore 29 extends from the upstream end portion 30 of the bore 25 and is inclined away from the radiator 10 at an acute angle to the bores 25, 27; the bore 29 communicates with the bore 27 as well as with the upstream end portion 30 of the bore 25. The axes of the bores 25, 27, 29 all lie in the same vertical plane. An inlet bore and an outlet bore 31, 33 for the return line 14 lead into the bore 25 at right angles to the bore 25 and their axes also lie in the same vertical plane as the axes of the bores 25, 27, 29.
[0014] The control valve 20 is secured in an enlarged portion of the bore 27 and comprises a thermostatic head 35 of known type and a conical valve member 37 arranged to move towards and away from a valve seating 39 to vary the flow from the bore 27 into the bore 25 in the operation of the valve assembly, and hence control the operation of the radiator 10.
[0015] The throttle valve 22 comprises a valve member 41 screwed into a threaded portion 43 of the bore 29 and arranged to move towards and away from a valve seating 45; the valve member 41 is provided with a screwdriver slot 47; the housing 23 is externally threaded around the valve member 41 to receive a screw end cap (not shown).
[0016] A plug 49 is fixed in the bore 25 between its junction with the bore 29 and the junction with the bore 31; and provides a transverse barrier isolating the upstream end portion 30 of the bore 25, from the remainder of the bore 25 which itself provides a bypass passage 51 in the horizontally extending portion of the housing 23, extending between the bores 31, 33 and series connected thereby to the return line 14.
[0017] The end portion 30 and the bores 29, 27 provide a branch passage adapted to connect the radiator duct 11 to the bypass passage 51; it will be noted that the end portion 30 is directly mechanically secured to the radiator duct 11.
[0018] The isolation valve 24 of the flow valve assembly 16 is mounted in a housing 53 of integral construction, the horizontally extending portion of which is also elongated along the axis of the radiator duct 11.
[0019] The housing 53 comprises a horizontal bore 55 which is coaxial with the radiator duct 11; and a bore 59 which extends from the downstream end portion 60 of the bore 55 and is inclined away from the radiator 10 at an acute angle to the bore 55. A bore 61 leads at right angles from the bore 55 and provides communication between the bores 55, 59. The axes of the bores 55, 59, 61 all lie in the same vertical plane. An inlet bore and an outlet bore 71, 73 for the flow line 12 lead into the bore 55 at right angles to the bore 55 and their axes lie in the same vertical plane as the axes of the bores 55, 59, 61; the bore 71 is coaxial with the bore 61.
[0020] The isolation valve 24 comprises a valve member 81 screwed into a threaded portion 83 of the bore 59 and arranged to move towards and away from a valve seating 85; the valve member 81 is provided with a screwdriver slot 87; the housing 53 is externally threaded around the valve member 81 to receive a screw end cap (not shown).
[0021] A plug 89 is fixed in the bore 55 between its junction with the bore 59 and its junction with the bores 61, 71; and provides a transverse barrier isolating the downstream end portion 60 of the bore 55 from the remainder of the bore 55 which itself provides a bypass passage 91 in the horizontally extending portion of the housing 53, extending between the bores 71, 73 and series connected thereby to the flow line 12. The bores 61, 59 and the end portion 60 provide a branch passage adapted to connect the bypass passage 91 to the radiator duct 11. It will be noted that the end portion 60 is directly mechanically secured to the radiator duct 11.
[0022] It will also be noted that a shoulder 96 is provided between the bores 61, 59, and the shoulder 96 extends upwardly from the bore 55 as shown in Figure 1.
[0023] In the operation of the apparatus, when the control valve 20 is open a portion of the water flowing through the bypass passage 91 of the flow valve assembly 16 is diverted through the bore 61, past the shoulder 96 into the bore 59, and thence to the radiator via the end portion 60 of the bore 55. The plug 89 prevents direct flow from the passage 91 into the end portion 60. The water exiting from the radiator passes into the end portion 30 of the bore 25 of the return valve assembly 18 and via the bore 29 and the bore 27, past the valve member 37 into the bypass passage 51 where it joins the return line water flowing through the bypass passage 51. The plug 49 prevents direct flow from the end portion 30 into the passage 51.
[0024] When the control valve 20 is closed, there is essentially no flow through the radiator and all the water from the flow and return lines 12, 14 flows directly through the bypass passages 91, 51 respectively.
[0025] When the valve assembly 16 is oriented as shown in Figure 1 the shoulder 96 provides a heat shield to minimise undesired convection heating of the radiator 10.
[0026] The throttle valve 22 is pre-set for flow balancing purposes and when it is required to isolate the radiator 10 the control valve 20 is positively closed and also the isolating valve 24: all flow is then necessarily through the bypass passages 91, 51.
[0027] The bores 31, 33 of the valve assembly 18 are interchangeable as inlet and outlet. When the boiler 15 is to the left of the radiators as shown in Figure 2, it may be convenient for 31 to provide the inlet and 33 to provide the outlet and vice versa when the boiler is to the right. The bores 71, 73 of the valve assembly 16 are similarly interchangeable as inlet and outlet.
[0028] In order to provide for continuous circulation of water, even when all the control valves 20 of all the radiators 10 are closed: at the terminal downstream radiator 10 (Figure 2) the bore 73 of the valve assembly 16 is connected to the bore 31 of the valve assembly 18 via a throttle 100; it will be realized that should it be desired to expand the number of radiators, it is a simple matter to remove this connection between the bores 73, 31 and to connect up additional radiators. Alternatively where continuous circulation is not considered important, the bores 73, 31 of the terminal downstream radiators can simply be closed with blind fittings, which still leaves the facility for expansion. In a simpler alternative a conventional flow and return valve can be used for the terminal downstream radiator, but then there is neither continuous circulation nor the facility for expansion, without replacing the valves of the terminal radiator.
[0029] Modern continuous flexible soft thin-walled copper or steel tubing or plastics tubing is used for the flow and return lines 12,14. All tube joints are readily accessible and are made using compression olives; joints underfloor or otherwise inaccessible are avoided. The tubing is of the kind typically used in single pipe central heating systems and is supplied in coils.
[0030] If of copper, the tubing is for example from 6 to 22 mm in outer diameter with a wall thickness of about 1 mm; it may be supplied pre-insulated with an outer sleeve of thermal insulating material, for example 2 to 3.5 mm in wall thickness. The copper tubing has for example the following properties:
[0031] If of steel, the tubing is for example from 10 to 18 mm in outer diameter with a wall thickness of about 1 mm, and may be plastic-coated against corrosion; again the steel tubing may be supplied pre-insulated with an outer sleeve of thermal insulating material for example 2 to 3.5 mm in thickness. The steel tubing has for example the following properties:
[0032] If of plastics (e.g. high density cross linked polyethylene), the tubing is for example from 10 to 28 mm in outer diameter with a wall thickness from 1.8 to 4.0 mm.
[0033] The main pipe runs may be within the floor, wall or ceiling, exposed or located within skirting. Figure 3 shows the main pipe runs within the floor with vertical branches extending above floor level for connection to the valve assemblies 16, 18. The absence of pipe connections below floor level will be noted.
[0034] A compression olive fitting is illustrated in Figure 4 with reference to the bore 31. A pipe 102 is received in the bore 31 and a compression olive 104 surrounds the end portion of the pipe 102. The olive 104 comprises opposed frusto-conical end portions and a cylindrical central portion. One end portion of the olive 104 is engaged by a complementary frusto-conical rim on the bore 31 and the other end portion of the olive is engaged by a corresponding rim on a nut 106. Tightening the nut results in the two rims camming the end portions of the olive into a sealing engagement.
[0035] The orientation of the valve assemblies 16, 18 about the axis of the radiator duct 11 can be varied according to floor, skirting or ceiling requirements, and this is facilitated by their radially compact axially elongated configuration.
[0036] It will be realized that all the flow valve assemblies 16 (and all the return valve assemblies 18) need not be on the same side of their respective radiators as shown in Figure 2: it is perfectly possible to have some radiators with the flow valve assembly 16 on the left and others on the right of the radiator according to convenience.
[0037] The thermostatically operated valve 20 may be replaced by a manually operable valve, or alternatively the return valve assembly 18 can be replaced by a valve assembly 16' (not shown) resembling the flow valve assembly 16 with the valve 24 of the return valve assembly 16' then being used for flow balancing purposes and the valve 24 of the flow valve assembly 16 replaced by a manually operable main control valve.
[0038] Again the extent to which a manual control valve is operable can be pre-set for flow balancing purposes; it will be realized here that the more remote the radiator is from the boiler, the wider the required maximum extent of opening of the valve.
[0039] A hand wheel provided on the isolation valve 24 could provide for instant manual shut off of the radiator over-riding the thermostatically operated valve 20.
[0040] The flow arrangement shown in Figure 5 resembles that shown in Figure 1 but the flow and return valve assemblies are somewhat modified. The valve assemblies of Figure 5 correspond in many respects to those of Figure 1 and are described insofar as they differ therefrom.
[0041] The return valve assembly of Figure 5 comprises a third bore 529 which extends from the upstream end portion 30 of the bore 25 and is inclined away from the radiator 10 at an acute angle to the bores 25, 27. The bore 529 leads into a bore 600 which extends at right angles from the bore 27 and the bores 529. 600 together provide communication between the end portion 30 of the bore 25, and the bore 27. The bore 600 extends beyond its junction with the bore 529 and the throttle valve member 41 is screwed into the bore 600, being arranged to move towards and away from a valve seating 545.
[0042] The flow valve assembly of Figure 5 comprises a bore 559 which extends from the downstream end portion 60 of the bore 55 and is inclined away from the radiator 10 at an acute angle to the bore 55. The bore 559 leads into a bore 561 which extends at right angles from the bore 55 and is coaxial to the bore 71; the bore 561 provides communication between the end portion 60 of the bore 55, and the bore 559. The bore 561 extends beyond its junction with the bore 559 and the isolation valve member 81 is screwed into the bore 561 being arranged to move towards and away from a valve seating 585.
[0043] In the modification of Figures 6 and 7 the return valve assembly 18 is replaced by a valve assembly 16" similar to 16' as described above but the flow valve assembly 16 is split into upper and lower valve assemblies 16a and 16b, respectively adjacent upper and lower portions of the radiator connected by a pipe 130. The main control valve 20 (thermostatic or manual) is provided in the upper valve assembly 16a, and the remainder of the flow paths are provided in the lower valve assembly 16b, as indicated by the arrows in Figure 7.
[0044] The valve assembly 16b (Figure 7) comprises a pipe connector 132 connected horizontally to the radiator 10 and vertically to the pipe 130. The valve assembly also comprises a body portion 134 abutting a sealing ring 136 between the pipe connector 132 and the body portion 134; the body portion 134 is connected to the flow line 12 by inlet and outlet bores 135, 137. An elongated screw member 138 is screwed into the pipe connector 132 and secures the body portion 134 to the pipe connector 132. A sealing ring 140 is provided between a head 139 of the screw member 138 and the body portion 134. It will be realized that loosening of the screw member 138 permits adjustment of the body portion 134 relative to the pipe connector 132 about the axis of the body portion 134 according to skirting requirements etc.
[0045] In the modification of Figure 8 the flow line 12 leads as a branch off a main vertical flow line 212 serving e.g. several floors of a multi-storey building with branch flow lines at each floor; and similarly the return line 14 leads as a branch to a main vertical return line 214. In this case it will be noted that the water flows concurrently along the flow and return lines 12, 14 rather than countercurrently as in Figure 2. The bore 73 of the valve assembly 16 of the right hand radiator 10 is blanked off, as is the bore 33 of the left hand radiator 10.
[0046] Other branch flow and return lines (not shown) may be run off in parallel flow connection with the lines 12, 14 to serve other areas of the building at the same floor level.
[0047] In the modification of Figure 9, the return line 14 in passing from one radiator 10 to the next passes through a pipe loop 314 which is located in a horizontal plane below floor level to provide heating through the floor surface.
[0048] It will be noted here that closing of the control valves 20 does not result in shutdown of the floor heating loops 314, which therefore remain as continuous background heating while the thermostatically controlled radiators act as a fine adjustment.
[0049] In the modification of Figure 10 the bore 33 of each return valve assembly 18 is connected to the i return line 14 via a floor heating pipe loop 414 and a common manifold 416. In this case the bores 31 are all blanked off.
1. Space heating apparatus adapted to be connected in a central heating system of
the double line fluid flow type, the apparatus comprising a space heating unit (e.g.
a radiator (10) of the hot water type), a flow valve assembly (16) adapted to connect
the heating unit (10) to a flow line (12) of the central heating system, and a return
valve assembly (18) adapted to connect the heating unit to a return line (14) of the
central heating system; each valve assembly (16, 18) comprising a bypass passage (91,
51) series-connectible to the flow or return line (12, 14) respectively, and a branch
passage (61, 59, 60; 30, 29, 27) connecting the bypass passage (91, 51) to the heating
unit (10), characterised in that the return valve assembly (18) is separate from the
flow valve assembly (16), and each valve assembly (16, 18) comprises a housing portion
which is elongated along an axis (e.g. the axis of a lower horizontal radiator duct
(11)) about which the valve assembly (16, 18) is mechanically secured to the heating
unit (10) and in which elongated portion is provided the bypass passage (91, 51).
2. Apparatus according to claim 1, wherein the branch passage comprises an end portion
(60, 30) which is directly mechanically secured to the heating unit (10); is provided
in said elongated housing portion coaxially with the bypass passage (91, 51), which
extends along said axis; and is isolated from the bypass passage by a transverse barrier
(89, 49).
3. Apparatus according to claim 1 or claim 2, wherein, in the return valve assembly
(18), the branch passage comprises a portion (27) which extends in the housing parallel
to the bypass passage (51), a control valve member (37) being provided to vary the
flow from said portion (27) of the branch passage into the bypass passage (51) in
the operation of the valve assembly.
4. Apparatus according to claim 1, wherein, in the flow valve assembly (16a, 16b),
the elongated housing portion is located adjacent a lower portion of the heating unit
and the branch passage comprises a portion (130) which extends from the housing to
a control valve (20) adjacent an upper portion of the heating unit and arranged to
vary the flow from the branch passage into the heating unit.
5. A flow or return valve assembly adapted for use in apparatus according to any one
of claims 1, 2 and 3, the valve assembly comprising a bypass passage (91, 51), series
connectible to the flow or return line (12, 14) and a branch passage (61, 59, 60;
30, 29, 27) adapted to connect the bypass passage (91, 51) to the heating unit (10),
characterised in that the valve assembly comprises a housing portion which is elongated
along an axis (e.g. the axis of a lower horizontal radiator duct (11)) about which
the valve assembly (16, 18) is mechanically securable to the heating unit (10), the
bypass passage (91, 51) is provided in the elongated portion and extends along said
axis; and the branch passage comprises an end portion (60, 30) which is directly mechanically
securable to the heating unit (10), is provided in said elongated housing portion
coaxially with the bypass passage (91, 51), and is isolated from the bypass passage
(91, 51) by a fixed transverse barrier (89, 49).
6. A return valve assembly according to claim 5, wherein the branch passage comprises
a portion (27) which extends in the housing parallel to the bypass passage (51), a
control valve member being provided to vary the flow from said portion (27) into the
bypass passage (51) in the operation of the valve assembly.
7. A double line central heating system comprising a plurality of heating units (10),
flow valve assemblies (16) and return valve assemblies (18) according to any one of
claims 1, 2, 3 and 4.
8. A double line central heating system according to claim 7, wherein the flow and
return lines (12, 14) to which the valve assemblies (18, 16) are connected are of
flexible tubing (e.g. of soft thin-walled copper or steel or of plastics) with all
joints (which are e.g. compression joints) readily accessible.
9. A double line central heating system according to claim 7 or claim 8, wherein in
the operation of the system continuous fluid circulation is maintained by appropriate
connection of the bypass passage (91) of a flow valve assembly (16) to the bypass
passage (51) of a return valve assembly (18).